DMD assembly and DLP projection device

ABSTRACT

The DMD assembly in present disclosure includes a base mounted on a first side of a driver board; a chip substrate; a DMD chip mounted on the chip substrate; and a fixing frame fixed with driver board on the first side; a second side of the base includes a mounting groove configured to mount the chip substrate; the fixing frame includes an insertion hole, and the base is received in the insertion hole; an elastic protrusion is positioned beside the inserting hole, and the elastic protrusion comprises a fixing portion and a pressing portion, the fixing portion is connected to the fixing frame on a side of the fixing frame facing away from the driver board, the pressing portion is positioned on the fixing portion; a surface of the pressing portion facing the chip substrate contacts the chip substrate to clamp the chip substrate against the base.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 15/600,950, which claims the benefit and priority of Chinese Patent Application No. 201610930022.7, filed Oct. 31, 2016, and Chinese Patent Applicant No. 201610932606.8, filed Oct. 31, 2016. The entire disclosures of the above applications are incorporated herein by reference.

FIELD

The present disclosure relates to the field of optical and projecting technology, and particularly to a DMD assembly and DLP projection device.

BACKGROUND

This section provides background information related to the present disclosure which is not necessarily prior art.

Because a digital light processing (DLP) projector is characterized by a high primary contrast, machine miniaturization and closed optical path, it is favored by users, and a DLP projector adopts a projecting technology where a digital micro-mirror device (DMD) chip acts as an imaging device to project an image by adjusting reflected light.

In related art, a DMD is connected to a driver board through multiple contacts. As shown in FIG. 1, a conventional connection between a DMD chip and a driver board is achieved by means of screws screwing the driver board to make the driver board press against corresponding contacts on the DMD chip.

SUMMARY

This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

Embodiments of the disclosure provide a DMD assembly. DMD assembly includes: a base mounted on a first side of a driver board; a chip substrate; a DMD chip mounted on the chip substrate; and a fixing frame fixed with driver board on the first side; a second side of the base includes a mounting groove configured to mount the chip substrate; the fixing frame includes an insertion hole, and the base is received in the insertion hole; an elastic protrusion is positioned beside the inserting hole, and the elastic protrusion comprises a fixing portion and a pressing portion, the fixing portion is connected to the fixing frame on a side of the fixing frame facing away from the driver board, the pressing portion is positioned on the fixing portion; a surface of the pressing portion facing the chip substrate contacts the chip substrate to clamp the chip substrate against the base.

Embodiments of the disclosure also provide a DLP projection device. The device includes a DMD assembly. The DMD assembly includes a base mounted on a first side of a driver board; a chip substrate; a DMD chip mounted on the chip substrate; and a fixing frame fixed with driver board on the first side; a second side of the base includes a mounting groove configured to mount the chip substrate; the fixing frame includes an insertion hole, and the base is received in the insertion hole; an elastic protrusion is positioned beside the inserting hole, and the elastic protrusion comprises a fixing portion and a pressing portion, the fixing portion is connected to the fixing frame on a side of the fixing frame facing away from the driver board, the pressing portion is positioned on the fixing portion; a surface of the pressing portion facing the chip substrate contacts the chip substrate to clamp the chip substrate against the base.

Further aspects and areas of applicability will become apparent from the description provided herein. It should be understood that various aspects of this disclosure may be implemented individually or in combination with one or more other aspects. It should also be understood that the description and specific examples herein are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

FIG. 1 is a schematic diagram of a dismantled structure of a DMD assembly according to related art.

FIG. 2 is a structural schematic diagram of a DMD assembly according to a typical embodiment of the present disclosure.

FIG. 3 is a schematic diagram of a dismantled structure of the DMD assembly illustrated in FIG. 2.

FIG. 4 is a structural schematic diagram of an assembly of a base and a chip substrate with a DMD chip in the DMD assembly illustrated in FIG. 2.

FIG. 5 is a schematic diagram of a dismantled structure of the assembly illustrated in FIG. 4.

FIG. 6 is a structural schematic diagram of a fixing frame in the DMD assembly illustrated in FIG. 2.

FIG. 7 is a structural schematic diagram of the driver board part (whose structure could also extend around) in the DMD assembly illustrated in FIG. 2.

FIG. 8 is a structural schematic diagram of a mounting plate in the DMD assembly illustrated in FIG. 2.

FIG. 9 is a structural schematic diagram of an assembly of a DMD chip substrate, a base and a driver board in the DMD assembly illustrated in FIG. 2.

FIG. 10 is a schematic diagram of a partly dismantled structure of the assembly illustrated in FIG. 9.

FIG. 11 is a structural schematic diagram of a DMD assembly according to another embodiment of the present disclosure.

FIG. 12 is a schematic diagram of a dismantled structure of the DMD assembly illustrated in FIG. 11.

FIG. 13 is a schematic diagram of another dismantled structure of the DMD assembly illustrated in FIG. 11.

FIG. 14 is a structural schematic diagram of a heat sink connection plate in the DMD assembly illustrated in FIG. 11.

FIG. 15 is a structural schematic diagram of a heat sink in the DMD assembly illustrated in FIG. 11.

Corresponding reference numerals indicate corresponding parts or features throughout the several views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference to the accompanying drawings.

Because in related art, the DMD chip is solely screwed to the driver board, and the contact between the DMD chip and the driver board is decided by the screwing of the screws, in this way the contacts between the DMD chip and the driver board are prone to displacement and separation due to other components or external factors, causing inaccurate and unsteady contact between the DMD chip and the driver board, which further results in quality problems of projected images.

Moreover, the related art also has the following problems:

1. as there should be an one-to-one match between each contact on the driver board and each contact on the DMD chip, but it is difficult to ensure precision, it is very likely that a contact on the driver boards does not fit a contact on the DMD chip, and high accuracy of relevant structural parts' sizes and installation is required;

2. the contacts on the driver broad and the contacts on the DMD chip should be firmly contacted with each other, but since it is difficult to ensure flatness of the DMD chip, uneven pressing forces might be caused, which further leads to poor contact between some contacts on the driver board and their corresponding contacts on the DMD chip; also, because of the great volume and weight of a rear heat sink, there is only a gap reserved to be filled with conductive gel between a protruding cooling block of the heat sink and the back of the DMD chip, the cooling block is prone to push the DMD chip under influences of forces from the heat sink or another element, leading to poor contact caused by separation of contacts on the DMD chip and contacts on the driver board, which further results in a dark area of a projected image, in other words, the projected image cannot be displayed normally, and repeated debug by a production-line work is required;

3. since the driver board is screwed to the DMD chip, axial displacement between the DMD chip and the driver board is prone to occur during a drop test and a vibration test, leading to low stability of contact;

4. the DVD chip and the driver board are not relatively fixed, bringing inconvenience to their assembly and dismantlement.

Therefore, it is necessary to improve the way how the DMD chip and the driver board are fixed together, so as to overcome the drawbacks and shortcomings of the foregoing related art. The present disclosure would be further described with reference to the figures and exemplary embodiments, where elements that are identical bear the same reference sign in all the figures. In addition, if detailed account of known art is unnecessary for showing characteristics of the present disclosure, it is omitted.

FIG. 2-10 illustrate schematic structural diagrams of a typical embodiment of a DMD assembly according to embodiments of the present disclosure, where the DMD assembly includes a chip substrate 1 with a DMD chip 10, a base 2 for installing the chip substrate 1, a mounting plate 5 and a fixing frame 3 both for fixing a driver board 4.

The chip substrate 1 is designed to be install into a mounting groove 22 set on the base 2, where the mounting groove 22 has an elastic stopper portion 23 configured to install and fix the chip substrate 1 within the mounting groove 22, the elastic stopper portion 23 preferably is made of plastic materials and is hook-like in shape, and a plurality of elastic stopper portions 23 are provided on the edges of the interior surface of the mounting groove 22, able to confine and fix the position of the chip substrate 1 which received by the mounting groove 22, making the chip substrate 1 unlikely to be released from the mounting groove 22. There are also a plurality of conductive spring leaves (without reference signs, and referring to the dots illustrated in FIG. 5) in the mounting groove 22, the arrangement of the conductive spring leaves corresponds to the arrangement of pin of bonding pads on the chip substrate. The conductive spring leaves extends from the plane where the mounting groove 22 is to the installed driver board 4 and the installed chip substrate 1 (“installed” refers to the structure of the DMD assembly illustrated in FIG. 2), so as to make an electrical connection between the chip substrate 1 and the driver board 4 situated on opposite sides of the base 2, where the position of each conductive spring leaf on the base 2 is pre-set according to positions of contacts on the chip substrate 1 and on the driver board 4. Moreover, a plurality of locating columns 24 are provided on a side of the base 2 which presses against the driver board 4 (i.e. the side opposite to the mounting groove 22), to facilitate accurate locating during installation of the driver board 4. A plurality of locating holes 42 matching the multiple locating columns 24 are provided at corresponding positions on the driver board 4. A locating structure constituted by the locating columns 24 and the locating holes 42 is not only able to better confine relative installation positions of the driver board 4 and the base 2, but is also able to guide the installation better, avoiding wrong locating of each contact, ensuring precise contact between each contact on the driver board 4 and each contact on the chip substrate 1, and the locating structure also facilitates the fixing of the driver board 4 to the base 2.

The fixing frame 3 includes an inserting hole 34 where the base 2 is inserted. The shape of the inserting hole 34 matches the shape of the base 2 correspondingly. A plurality of elastic protrusion 32 are provided on edges enclosing a side of the inserting hole 34 (the side opposite to the side from which the base 2 is inserted/removed, i.e. the side of the fixing frame away from the driver board). Once the base 2 containing the chip substrate 1 is inserted into the hole 34 from the insertion side, each elastic protrusion 32 would hook interior surface of an edge of the mounting groove 22, engaging the elastic protrusion 32 and the edge of the mounting groove 22, and making the elastic protrusions 32 pressing against edges of the chip substrate 1 firmly, wherein the interior surface corresponds to the elastic protrusion 32.

The elastic protrusion 32 includes a fixing portion 321 connected to the fixing frame 3, and a pressing portion 322 on the fixing frame 321, where the surface of the pressing portion facing the chip substrate 1 of the pressing portion contacts the chip substrate 1, so as to press the chip substrate 1 firmly onto the base 2; the surface of the pressing portion 322 facing the mounting groove's side surface contacts the mounting groove's side surface, so as to cooperate with the inserting hole to confine the position of the base 2.

The fixing portion 321 includes a supporting portion 3211 perpendicular to the fixing frame 3 and a turning portion 3212 on the supporting 3211, extending to the inserting hole. The fixing portion 322 is on the side of the turning portion 3212 facing the driver board 4.

Alternatively, the fixing frame 3 is made of 0.8-1 mm thick SECC sheet metals, and the fixing frame 3 is integrally molded with the three elastic protrusions 32; because the SECC material has a certain degree of elasticity, the elastic protrusions 32 would not crush or damage ceramic parts on the edges of the DMD chip 10 when contacting edges of the chip substrate 1, not only the hook-like elastic protrusions 32 could hook interior surface on the edges of the mounting groove 22, but there is interference contact between the elastic protrusions 32 and surfaces of ceramic parts on edges of the DMD chip 10 (i.e. there is interference contact between surfaces of the pressing portions facing the chip substrate and surfaces of ceramic parts on edges of the DMD chip 10) as well, and the interference is approximately 0.3 mm, so that the elastic protrusions 32 could be slightly deformed when contacting the ceramic parts on the edges of the DMD chip 10, pressing the DMD chip 10 firmly, making it difficult for the DMD chip 10 to shake and shift, further ensuring precise and stable contact between contacts on the DMD chip 10 and the contacts on the driver board 4.

In some embodiments, a first through hole is provided on the driver board 4, and a second through hole is provided on the fixing frame 3, where the first through hole's position corresponds to the second through hole's position, and the driver board 4 is fixed to the fixing frame 3 by a fastener (such as a bolt, a nut etc.) through the first through hole and the second through hole.

In some embodiments, because threaded holes cannot be made onto the driver board 4, but the driver board 4 needs to be well fixed to the chip substrate 1, the mounting plate 5 could be configured to cooperate with the fixing frame 3 to fix the driver board 4, that is, there is a third through hole (such as a threaded hole) on the mounting plate 5, and the position of the third through hole corresponds to the position of the first hole, thus steadily fixing positions of the driver board 4 and the chip substrate 1 inserted in the fixing frame 3, by screwing a fixing screw 8 into the threaded hole on the mounting plate 5 through the fixing frame 3 (the second through hole) and the driver board 4 (the first through hole). In this way, not only relative positions of the driver board 4 and the chip substrate 1 are steadily fixed, but, as the mounting plate 5 and the fixing frame 3 are situated on opposite sides of the driver board 4 respectively, forces exerted on the opposite sides of the driver board 4 could be well balanced as well, avoiding deformation of the driver board 4 and displacement of contacts on the driver board 4, and ensuring precise and steady contact between contacts on the chip substrate 1 and contacts on the driver board 4.

Moreover, a plurality of locating columns 54 are provided on the side of the mounting plate 5 which presses the driver board 4 to facilitate accurate locating during installation of the driver board 4, and a plurality of locating holes 45 matching the multiple locating columns 54 are provided on corresponding positions of the driver board 4. Similarly, a plurality of locating holes 33 matching the locating columns 54 are provided on corresponding positions of the fixing frame 3, a locating structure constituted by the locating columns 54, the locating holes 45 and the locating holes 33 has a similar effect to the abovementioned locating structure between the base 2 and the driver board 4. Alternatively, the mounting plate 5 is made of 2.5 mm thick aluminum alloy die casting, and 4 fixing screws 8 of M3×6 mm, evenly distributed, are used to screw the mounting plate 5, the driver board 4 and the fixing frame 3 together, in which way pressures applied to the driving board 4 and the chip substrate 1 are made even, avoiding poor contact of contacts.

Alternatively, assembly of each relevant element of the DMD assembly is described as follows.

First, fitting the chip substrate 1 to the mounting groove 22 of the base 2, where when fitting the chip substrate 1, the elastic stopper portion 23 on the edges of the interior surface of the mounting groove 22 would fix and confine the position of the chip substrate 1 well, each conductive spring leaf in the mounting groove 22 would contact a corresponding position on the chip substrate 1 precisely and steadily.

Then, insert the base 2 containing the chip substrate 1 to the inserting hole 34 on the fixing frame 3, with the side of the base 2 which receives the chip substrate 1 protruding from the side of fixing frame 3 with elastic protrusions 32, so that each elastic protrusion 32 is caught between the interior surface of an edge of the DMD chip 10 and the interior surface of an edge of the mounting groove 2 corresponding to the elastic protrusion, respectively, and hooks the interior surface the edge of the mounting groove 2, where each elastic protrusion 32 contacts and presses an edge of the DMD chip 10, making each elastic protrusion 32 slightly deformed to better press and fix the DMD chip 10, so that the DMD chip 10 is electrically connected to the driver board 4 through the conductive spring leaves in a precise and stable manner.

Then, under the guidance of the locating columns 24 on the base 2, pressing the driver board 4 firmly against the back of the base 2 (which is opposite to the side receiving the chip substrate 1), so that each contact of the driver board 4 contacts each conductive spring leaf extending from the mounting groove 22 correspondingly, as a result, each contact of the chip substrate 1 corresponds to each contact of the driver board 4 in a one-to-one match; subsequently, fitting locating columns 54 on the mounting plate 5 into corresponding locating holes 45 on the driver board 4 and locating holes 33 on the fixing frame 33, and pressing the mounting plate 5 firmly against the driver board 4, after which, screwing 4 fixing screws 8 into threaded holes on the mounting plate 5 through the fixing frame 3 and the driver board 4, so that relevant elements closely contact one another, which further leads to stable fixing and contact between elements, especially precise and stable contact between each contact on the chip substrate 1 and each contact on the driver board 4.

Moreover, FIG. 2-15 illustrates a DMD assembly according to another embodiment of the present disclosure, where based on the DMD assembly according to the foregoing embodiment, this embodiment adds a heat sink 7 to cool the chip substrate 1 and a heat sink connection plate 6 inserted into the chip substrate 1.

Alternatively, an inserting dowel 62 is provided on the heat sink connection plate 6, and an inserting slot 12 matching the inserting dowel 62 is provided on the chip substrate 1. The inserting slot 12 is on the ceramic part of an edge of the chip substrate 1; the inserting slot 12 and portions of the edge which contact the elastic protrusions are staggered with each other. When the inserting dowel 62 inserts into the inserting slot 12, it presses the ceramic part of the chip substrate 1 to form a hard contact. A locating column 26 is provided on the side of the base 2 with the mounting groove 22 to facilitate locating during installation of the heat sink connection plate 6. A locating hole 64 matching the locating column 64 is provided on the heat sink connection plate 6, and a locating structure constituted by the locating column 26 and the locating hole 64 has a similar effect to the abovementioned locating structures (such as the locating structure between the base 2 and the driver board 4). Alternatively, there are three sets of inserting dowels 62 and inserting slots 12 and the heat sink connection plate 6 is made of aluminum alloy.

The heat sink 7 includes a cooling block 71, which protrudes the end face 72 of heat sink 7, wherein the end face 72 presses the mounting plate 5. A fourth through hole is provided on the end face 72, and the position of the fourth through hole corresponds to the position of the third through hole. Penetrating holes through which the cooling block 71 can go are provided on corresponding positions of the driver board 4, the mounting plate 5 and the base 2, so that the cooling block 71 could go through each penetrating hole to contact the back of the DMD chip 10 (the side which electrically connected to the driver board 4 through the conductive spring leaf). Alternatively, the cooling block 71 contacts the DMD chip 10 by conductive gel.

The heat sink 7 extends through the mounting plate 5 and the driver board 4, and rigidly connects to the heat sink connection plate 6 via a screw, such as a shoulder screw 9, as well as a spring 91 in cooperation with the shoulder screw 9, where a threaded stud 63 matching the should screw 9 is provided on the heat sink connection plate 6. This connection method avoids poor contact of contacts due to separation of the driver board 4 and the chip substrate 1 because of gravity of the heat sink 7, steadily fixing each relevant element, improving a product's quality and lowering defect rate of relevant products. Alternatively, four sets of shoulder screws 9, springs 91 and threaded studs 63 are evenly distributed on corresponding elements, respectively. The spring 91 is fitted to the shoulder screw 9, i.e., one end of the spring 91 abuts the nut of the shoulder screw 9. The diameter of the fourth through hole on the end face 72 is larger than the diameter of the third through hole on the mounting plate 5, so that the other end of the spring 91 extends through the end face 72 and abuts the mounting plate 5.

Each element of the DMD assembly according to this embodiment could be assembled on the basis of the foregoing embodiment.

Under the guidance of the locating columns 63 on the base 2 corresponding to the heat sink connection plate 6, inserting each inserting dowel 62 on the heat sink connection plate 6 into a corresponding inserting slot 12 on the chip substrate 1; subsequently, pressing the cooling block 71 on the heat sink 71 through penetrating holes on the mounting plate 5, driver board 4 and base 2 and against the back of the chip substrate 1; finally, screwing four composite structures each consisting of a shoulder screw 9 and a spring 91 into threaded studs 63 on the heat sink connection plate 6 through the heat sink 7, mounting plate 5 and driver board 4, so that relevant elements closely contact one another, which further leads to stable fixing and contact between elements, especially precise and stable contact between each contact on the chip substrate 1 and each contact on the driver board 4.

Alternatively, there are two sets of locating structures between the base 2 and the driver board 4, between the mounting plate 5 and the driver board 4 (fixing frame 3), and between the base 2 and the heat sink connection plate 6, respectively, each set including a locating column and a locating hole.

In some embodiments, a spring and a spring leaf are fitted to a should screw 9, where a first end of the spring leaf abuts the nut of the shoulder screw 9, a second end of the spring leaf abuts a surface area of the end face 72, wherein the surface area faces to the nut of the shoulder screw 91, the first end of the spring leaf locates between the nut of the shoulder screw 9 and a first end of the spring, and the other end of the spring abuts the mounting plate 5 through the fourth through hole on the end face 72.

Some embodiments provides another DMD assembly, the DMD assembly includes a chip substrate with a DMD chip, a heat sink connection plate, a driver board electrically connected to the chip substrate through contacts, a mounting plate and a heat sink, where the heat sink includes a cooling block, which protrudes from the end face of the heat sink contacting the mounting plate. Penetrating holes through which the cooling block penetrates, are provided on the driver board and the mounting plate, and the penetrating holes correspond to the side of the chip substrate facing the driver board; the cooling block penetrates through the penetrating holes on the mounting plate and the driver board to contact the side of the chip substrate facing the driver board. Any of the connections described in the foregoing embodiments, as well as any connection disclosed in related art could exist among the mounting plate, the driver board and the chip substrate.

Some embodiments provide a DMD assembly, which includes a base, a driver board, a chip substrate with a DMD chip and a fixing frame. Structures of the base, the driver board, the chip substrate and the fixing frame are similar to descriptions of these elements in foregoing embodiments, which will not be discussed here anymore. The DMD assembly also includes a heat sink, which includes a cooling block protruding from an end face of the heat sink contacting the driver board; penetrating holes through which the cooling block penetrates are provided on the driver board and the base, and the penetrating holes correspond to a side of the chip substrate facing the driver board; the cooling block contacts the side of the DMD chip facing the driver board through penetrating holes on the driver board and the base.

In the DMD assembly according to the present disclosure, a plurality of conductive spring leaves on the base extends from the mounting groove to contact a side of the driver board, inserting holes on the fixing frame facilitates the base's insertion into the fixing frame, and a plurality of elastic protrusions are provided on edges enclosing a side of the inserting hole. During installation, inserting the base holding the DMD chip from one side of the fixing frame into the fixing frame, and making the elastic protrusions on the other side of the fixing frame hook edges of the mounting groove of the base where the DMD chip is inserted and press the DMD chip, so that the DMD chip is steadily contained in the mounting groove and contacts the conductive spring leaf precisely and stably; then pressing the driver board against the side of the base opposite to the elastic protrusions, and fixing the driver board to the fixing frame or clamp the driver board between the fixing frame and the mounting plate with a fastener, so that the driver board contacts the conductive spring leaves on the base and electrically connects to the DMD chip in the mounting groove via the conductive spring leaves. In this way, the driver board and the DMD chip could be fixed and connected in a precise and stable manner, displacement and separation of the DMD chip, the driver board and respective corresponding conductive spring leaves (that is, contacts) are not likely to happen, contact between the DMD chip and the driver board is precise and stable, and assembly and dismantlement for DMD assembly are both convenient.

Moreover, the heat sink is rapidly connected to the heat sink connection plate through shoulder screws and springs fitted to the shoulder screws which extend through the mounting plate, the driver board and the fixing frame. An inserting dowel on the heat sink connection plate and a inserting slot matching the inserting dowel on the chip substrate could effectively prevent the cooling block from pushing the DMD chip because of forces from the heat sink or another element, thus avoiding poor contact and bad impact on a projected image due to separation of contacts on the DMD chip and contacts on the driver board, further improving precision and stability of contact between contacts on the DMD chip and contacts on the driver board, and improving quality of the projected image.

Moreover, there is interference contact between the elastic protrusions and the surface of the ceramic parts on the edge of the DMD chip, and the elastic protrusions press the DMD chip, so that the DMD chip is steadily held by the mounting groove and the DMD chip closely and stably contacts the conductive spring leaves after installation, which further improves precision and stability of contact of contacts on the DMD chip and contacts on the driver board; the fixing frame is made of elastic sheet metal material, because the elastic sheet metal material has a certain degree of elasticity, the elastic protrusions on the fixing frame would not crush or damage ceramic parts on edges of the DMD chip when pressing into edges of the mounting groove, ensuring integrity of relevant elements during installation, reducing installation difficulty and improving production efficiency as well as product quality.

In addition, DMD assemblies according to foregoing embodiments could be applied to a DLP projection device, in other words, some embodiments of the present disclosure also provides a DLP projection device, and DLP projection device includes a DMD assembly according to any of the foregoing embodiments, so that the DLP projection device applying the foregoing DMD assembly also have all the advantages of the foregoing DMD assembly.

In conclusion, embodiments of the present disclosure could not only ensure precision and stability of contact between the contacts on the DMD chip and the contacts on the driver board, improving the quality of the projected image, but reducing dismantlement difficulty and lowering requirements for the sizes of relevant structural elements as well, improving production efficiency and reducing production costs.

The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure. 

The invention claimed is:
 1. A DMD assembly comprising: a base mounted on a first side of a driver board; a chip substrate; a DMD chip mounted on the chip substrate; and a fixing frame fixed with the driver board on the first side, wherein: a first side of the base includes a mounting groove configured to mount the chip substrate; the fixing frame includes an insertion hole, and the base is received in the insertion hole; an elastic protrusion is positioned beside the insertion hole; the elastic protrusion comprises a fixing portion and a pressing portion, the fixing portion is connected to the fixing frame on a side of the fixing frame facing away from the driver board, and the pressing portion is positioned on the fixing portion; and a surface of the pressing portion facing the chip substrate contacts the chip substrate to clamp the chip substrate against the base.
 2. The DMD assembly according to claim 1, wherein the fixing portion comprises a turning portion and a supporting portion, one end of the supporting portion is connected with the fixing frame and another end of the supporting portion is connected with the turning portion, the turning portion extends from the another end of the supporting portion to an axis of the insertion hole, and the pressing portion is positioned on a side of the turning portion facing the driver board.
 3. The DMD assembly according to claim 1, wherein the elastic protrusion is integrally molded with the fixing frame.
 4. The DMD assembly according to claim 1, wherein an interference contact is positioned between the surface of the pressing portion facing the chip substrate and a surface of the chip substrate.
 5. The DMD assembly according to claim 4, wherein: the surface of the chip substrate facing the pressing portion is an upper surface of the chip substrate where the DMD chip is mounted.
 6. The DMD assembly according to claim 1, wherein: the driver board is on a third second side of the base opposite to the first side of the base, the fixing frame includes a first through hole and the driver board includes a second through hole whose position corresponds to the position of the first through hole; and a first fastener fixes the driver board and the fixing frame through the first through hole and the second through hole.
 7. The DMD assembly according to claim 6, wherein: a locating column is positioned on the first side of the driver board where the driver board is attached to the fixing frame; and the fixing frame includes a first locating hole, and the first locating hole matches the locating column.
 8. The DMD assembly according to claim 1, wherein the driver board is on a second side of the base opposite to the first side of the base, the fixing frame includes a first through hole and the driver board includes a second through hole, and the DMD assembly further comprises: a mounting plate on a second side of the driver board opposite to the first side of the driver board, the mounting plate including a third through hole whose position corresponds to the position of the first through hole and the second through hole; and a fastener that fixes the mounting plate, the driver board and the fixing frame together through the first through hole, the second through hole and the third through hole.
 9. The DMD assembly according to claim 8, wherein: a first locating column is located on a side of the mounting plate where the mounting plate is attached to the driver board; and the driver board includes a first locating hole, the fixing frame includes a second locating hole, and the first locating hole and the third second locating hole match the first locating column together.
 10. The DMD assembly according to claim 9, wherein the second side of the base includes a second locating column, the driver board includes a third locating hole, and the third locating hole matches the second locating column.
 11. The DMD assembly according to claim 1, wherein a side wall of the mounting groove includes an elastic stopper, and the elastic stopper abuts an edge of the chip substrate to confine a position of the chip substrate.
 12. A DLP projection device, comprising: a DMD assembly, wherein the DMD assembly comprises: a base mounted on a first side of a driver board; a chip substrate; a DMD chip mounted on the chip substrate; and a fixing frame fixed with the driver board on the first side, wherein: a side of the base facing away from the driver board includes a mounting groove configured to mount the chip substrate; the fixing frame includes an insertion hole, and the base is received in the insertion hole; an elastic protrusion is positioned beside the insertion hole and the elastic protrusion comprises a fixing portion and a pressing portion, the fixing portion is connected to the fixing frame on a side of the fixing frame facing away from the driver board, and the pressing portion is positioned on the fixing portion; and a surface of the pressing portion facing the chip substrate contacts the chip substrate to clamp the chip substrate against the base. 